U.S. Pat. No. 4,186,406 to Bahr et al. and commonly assigned relates to a multi-electro printhead for electroerosion printers. Apparatus and a method of providing a multiplex control for the plurality of electrodes is provided using a technique which allows the elimination of a number of control leads. A single line is commonly arranged to carry all energizing signals to all electrodes. The decoding means is provided to condition individual electrodes during energization. Circuit means is provided for energizing each pair of electrodes through a portion of the circuit common to both electrodes by rendering the individual electrodes responsive only to a particular polarity of electrical signal energization. This patent teaches a movable printhead controlled by a circuit which utilizes the concept of activating two adjacent electrodes via one common printhead line at different times wherein the activation pulse applied at different times is of opposite to polarities.
U.S. Pat. No. 3,846,801 to DuMont et al. relates to electrographic drawing apparatus comprising a multiplicity of writing electrodes in contact with electrosensitive paper. The signals are distributed to the respective electrodes by time division demultiplexers. Electrodes are preferably energized in a progressive sequence in which each is connected for energization after the preceding one in line.
U.S. Pat. No. 3,825,776 to Jacquart and commonly assigned teaches a switchable current generator for selectively establishing current loops for providing high stable null, and equal but opposite polarity currents dependent only on resistive means.
U.S. Pat. No. 3,732,573 to Merka et al. relates to an electrographic printer having a multiplex matrix driving circuit which reduces the number of switches needed to drive the stylic.